The present invention relates to a lifting machine and more particularly pertains to an easily operated crane.
A conventional crane comprises a base, a post, a boom and an oil cylinder. The base has a bottom side with is disposed with freely movable rollers. The post is vertically disposed on the base. The boom is pivotally mounted to a top end of the post and is provided with a hook at a front end thereof for hanging a heavy load. The oil cylinder functioning as actuating mechanism has a cylinder body pivotally mounted to the post and a piston rod extending upward. The piston rod has a top end which is pivotally mounted to the boom. During operation, the operator manually pulls the handle of the oil pump up and down to deliver hydraulic oil, and the hydraulic oil drives the piston rod in the oil cylinder to move upwards to press against the boom. The boom is then driven to rotate anti-clockwise around the pivotal point, thereby lifting the heavy load hung on the hook.
The disadvantage of this kind of crane is that the operation position of the oil pump handle is relatively fixed. This restricts the activity of the operators to a certain fixed position. As a result, the crane fails to adapt to various kinds of working environments and is therefore limited in application areas.